1. Field of the Invention
This invention relates to a control apparatus used for the process control of semiconductor device manufacturing equipment such as cluster tool equipment and a method therefor.
2. Discussion of the Background
In general, a process chamber for performing various processes such as a CVD (chemical vapor deposition) process or a sputtering process, an etching process, and a thermal oxide process for semiconductor wafers W is provided in the upstream thereof with a cassette chamber which has cassettes capable of containing a plurality (twenty five, for example) of the wafers W. The wafers are transferred from the cassette chamber to the process chamber via a transfer chamber.
A transfer chamber is generally connected to a plurality (three, for example) of process chambers such that the wafers are transferred from the cassette chamber to the process chambers via the transfer chamber so as to be subjected to the various processes.
In such a system, the process chamber must be sometimes replaced or cleaned due to the contamination by the deposition of the reactive product produced during the processes, for example. In that time, the operation of the process chamber must be stopped during the maintenance or cleaning. If one of the three process chambers needs to be maintained or cleaned, it is preferable in view of the manufacturing efficiency that the operation of only the process chamber which needs to be maintained or cleaned is stopped to be maintained or cleaned and the other process chambers continue to operate.
In the most case, however, the operations of the transfer chamber, the cassette chamber, and the process chambers are controlled by process control by which the operations of the chambers are closely related to each other. It is thus very difficult to control the units so as to stop the operation of only the specified one process chamber as described above. More specifically, when the operation of only specified one process chamber is desired to be stopped, not only the program for controlling the specified one process chamber but also the program for controlling all the process chambers inclusively and the programs for controlling the cassette chamber and the transfer chamber need to be changed.